Introduction

The main printed circuit board in a

computer is known as the Motherboard. It

is also known as System Board, Main

Board or Printed Wired Board (PWB). It is

also sometimes abbreviated or shortened

to Mobo. Attached to it, we have

numerous motherboard components that

are crucial in the functioning of the

computer.

The motherboard acts as the connection

point where major computer

components are attached to. It holds

many of the crucial components of the

system like the processor, memory,

expansion slots and connects directly or

indirectly to every part of the PC.

The type of motherboard installed in a PC

has a great effect on system speed and

expansion capabilities.

Motherboard Components

The motherboard holds all the major logic

components of the computer.

Here we are going to see with no

particular order, some of these major

motherboard components and their

function in a computer.

The diagram above shows the major component of

a motherboard

PARTS OF THE MOTHERBOARD

CPU- Central Processing Unit

It is also known as the microprocessor or

the processor. It is the brain of the

computer, and it is responsible for

fetching, decoding and executing

program instructions as well as performing

mathematical and logical calculations.

The processor chip is

identified by the processor

type and the

manufacturer; and this

information is usually

inscribed on the processor

chip e.g. Intel 386,

Advanced Micro Devices

(AMD) 386, Cyrix 486,

Pentium MMX, (old

processor types) Intel

Core 2Duo, iCore7 and

many more.

If the processor chip is not

on the motherboard, you

can identify the processor

socket as socket 1 to

Socket 8, LGA 775 among

others. This can help you

identify the processor that

fits in the socket. For

example a 486DX

processor fits into Socket

3.

LGA 775 SOCKET

Main Memory /

Random Access Memory (RAM)

Random Access Memory or RAM most

commonly refers to computer chips that

temporarily store dynamic data when you are

working with your computer to enhance the

computer performance.

In other words, it is the working place of your

computer where active programs and data are

loaded so that any time the processor requires

them, it doesn't have to fetch them from the hard

disk which will take a longer access time.

Random access

memory is volatile

memory, meaning it

loses its contents

once power is turned

off. This is different

from non-volatile

memory such as hard

disks and flash

memory, which do not

require a power

source to retain data. KINGSTON TECH. 8GB

DDR3 RAM

When a computer shuts down properly, all

data located in Random Access Memory is

returned back to permanent storage on the

hard drive or flash drive. At the next boot-

up, RAM begins to fill with programs

automatically loaded at startup, a process

called booting. Later on, the user opens

other files and programs that are still

loaded in the memory.

BIOS- Basic Input Output

System BIOS is a term that stands for Basic

Input/Output System. BIOS is a Read Only

Memory which consists of low-level software that

controls the system hardware and acts as an

interface between the operating system and the

hardware. Most people know the term BIOS by

another name—device drivers, or just drivers.

BIOS is essentially the link between the

computer hardware and software in a system.

All motherboards include

a small block of Read

Only Memory (ROM)

which is separate from

the main system memory

used for loading and

running software. On

PCs, the BIOS contains

all the code required to

control the keyboard,

display screen, disk

drives, serial

communications, and a

number of miscellaneous

functions.

KINGSTON TECH. 8GB

DDR3 RAM

CMOS RAM - Complimentary Metal

Oxide Semiconductor Random

Access Memory Motherboards also

include a small separate

block of memory made

from CMOS RAM chips

which is kept alive by a

battery (known as a

CMOS battery) even

when the PC’s power is

off. This prevents

reconfiguration when the

PC is powered on.CMOS BATTERY

CMOS devices require very little power to operate.

The CMOS RAM is used to store basic Information about

the PC’s configuration for instance:-

Floppy disk and hard disk drive types

Information about CPU

RAM size

Date and time

Serial and parallel port information

Plug and Play information

Power Saving settings

The Other Important data kept in CMOS memory is the

time and date, which is updated by a Real Time Clock

(RTC).

Cache Memory

It is a small block of high-speed memory

(RAM) that enhances PC performance by pre-

loading information from the (relatively slow)

main memory and passing it to the processor on

demand.

Most CPUs have an internal cache memory (in-

built in the processor) which is referred to as

Level 1 cache memory or primary cache

memory. This can be supplemented by external

cache memory fitted on the motherboard. This is

the Level 2 Cache memory or secondary cache.

In modern

computers, we are

having Level 1 and

2 cache memory

build into the

processor die. If a

third cache is

implemented

outside the die, it is

referred to as the

Level 3 (L3) cache.L2 CACHE OF AN OLD

MOTHERBOARD

Expansion Bus

This is an input/output pathway from the

CPU to peripheral devices typically made

up of a series of slots on the motherboard.

Expansion boards (cards) plug into the

bus. PCI is the common expansion bus in

a PC and other hardware platforms. Buses

carry signals, such as data, memory

addresses, power, and control signals

from component to component.

Expansion buses enhance the PCs

capabilities by allowing users to add

missing features in their computers in form

of adapter cards that are slotted in

expansion slots.

The different types of buses include PCI,

ISA, and EISA expansion bus among

others.

Chipsets

A chipset is a group of small circuits that

coordinate the flow of data to and from key

components of a PC. This includes the

CPU itself, the main memory, the

secondary cache and any devices situated

on the buses. The chipset also controls

data flow to and from hard disks, and other

devices connected to the IDE channels. A

computer has got two main chipsets:

The NorthBridge (also called the memory controller)

is in charge of controlling transfers between the

processor and the RAM, which is why it is located

physically near the processor. It is sometimes called

the GMCH, for Graphic and Memory Controller Hub.

The SouthBridge (also called the input/output

controller or expansion controller) handles

communications between slower peripheral devices.

It is also called the ICH (I/O Controller Hub). The

term bridge is generally used to designate a

component which connects two buses.

Chipset manufacturers include SIS, VIA, ALI, OPTI

among others.

CPU Clock

The clock synchronizes the operation of all

parts of the PC and provides the basic

timing signal for the CPU. Using a quartz

crystal, the CPU clock breathes life into

the microprocessor by feeding it a

constant flow of pulses.

For example, a 200 MHz CPU receives 200

million pulses per second from the clock. A 2

GHz CPU gets two billion pulses per second.

Similarly, in any communications device, a clock

may be used to synchronize the data pulses

between sender and receiver.

A "real-time clock," also called the "system

clock," keeps track of the time of day and makes

this data available to the software. A "time-

sharing clock" interrupts the CPU at regular

intervals and allows the operating system to

divide its time between active users and/or

applications.

Switches and Jumpers

DIP (Dual In-line Package) Switches and Jumpers DIP (Dual In-line

Package) switches are small electronic switches

found on the circuit board that can be turned on

or off just like a normal switch. They are very

small and so are usually flipped with a pointed

object such as the tip of a screwdriver, bent

paper clip or pen top. Care should be taken

when cleaning near DIP switches as some

solvents may destroy them. Dip switches are

obsolete as you will not find them in modern

systems.

DIP SWITCH

Jumper pins

Jumpers are small protruding pins on the

motherboard. A jumper cap or bridge is

used to interconnect or short a pair of the

jumper pins. When the bridge is connected

to any two pins via a shorting link, it

completes the circuit and a certain

configuration has been achieved.

Jumper cap

A metal bridge that closes an electrical circuit.

Typically, a jumper consists of a plastic plug that

fits over a pair of protruding pins. Jumpers are

sometimes used to configure expansion boards.

By placing a jumper plug over a different set of

pins, you can change a board's parameters.

NOTE: A sure place you can check jumper pins

and jumper cap is at the back of an IDE hard

disk and CD/DVD ROM/Writer.

JUMPER PINS WITH A CAP ON

Suggested Video

Motherboard Forms, Factors and

Components:

http://youtu.be/NTAicmPLYvQ

Reference:

http://patkay.hubpages.com/hub/the-

motherboard-components#